Prevalence of migraine and tension‐type headache among undergraduate medical students of Kathmandu Valley: A cross‐sectional study

Abstract Background Headache is the most prevalent neurological symptom which can be of a serious condition, as in brain tumor, but mostly it is a benign condition that includes primary headache such as migraine or tension‐type headache (TTH). Migraine reoccurs frequently and is more severe but owing to the high prevalence of TTH, however, impaired quality of life due to TTH is greater than that of migraine at the population level. Medical students are constantly subjected to stress and in such a condition, it was necessary to find out the burden of headache among medical students. This cross‐sectional study done among medical students aims to generate some data and literature which will change the outlook of stakeholders towards headache disorders among medical students. Methods This cross‐sectional study is based upon Headache Screening Questionnaire—English Version questionnaire based upon the ICHD‐3 beta criteria. Medical students of Kathmandu valley were sampled by using convenient sampling and data were collected. Data were refined in Microsoft Excel and imported to SPSS 20 for analysis. Results A total of 352 individuals were part of this study, out of which 229 (65.1%) were males and 123 (34.9%) were females with a mean age of 21.72 ±  1.601 years (mean ± SD). Prevalence of migraine and TTH was found to be 15.3% (95% confidence interval [CI]: 11.7%–19.3%) and 40.3% (95% CI: 34.9–45.2), respectively. Through multivariate binomial regression, it was observed that the odds of being diagnosed with migraine increased with age (adjusted odds ratio [AOR] = 1.266 [1.013–1.583], p = 0.038), females had twice the odds of experiencing migraine headaches compared to males (AOR = 2.119 [1.074–4.180], p = 0.03), and medical students who stayed at the hostel were at lesser odds of experiencing migraine headache (AOR = 2.772 [1.501–5.118], p = 0.01). Conclusion Prevalence of migraine and TTH among undergraduate medical students was found to be 15.3% and 40.3%, respectively.


| BACKGROUND
Headache is the most prevalent neurological symptom which is experienced by almost everyone at least once in their lifetime. 1 This neurological symptom can be of a serious condition, as in brain tumor, but mostly it is a benign condition that includes primary headache such as migraine or tension-type headache (TTH). 2 Migraine and TTH are a matter of importance to global public health because they impose a widespread burden of ill health and impaired quality of life. 3 International Headache Society differentiates migraine and TTH according to their frequency of occurrence, severity, intensity, anatomical involvement of the head, aggravating factors, and associated factors. In contrast to TTH, migraine reoccurs frequently, is more severe, has unilateral involvement, pulsating quality, is aggravated by routine physical activities, and is associated with nausea and/or photophobia and phonophobia. 4 But, owing to the high prevalence of TTH (globally, 11% for migraine, 42% for TTH), impaired quality of life due to TTH is greater than that of migraine at the population level. 3 The burden of ill health and impaired quality of life due to headache remains large and it is estimated that it costs a minimum of US$100 million per million inhabitants per year. 2 In a domestic study within Nepal, headache was seen as one of the most prevalent painful conditions. 5 Medical students are constantly subjected to stress regarding their academics, performance, exams, and responsibilities. In such circumstances, medical students are prone to experience headaches and this study aims to find out the prevalence of primary headache (migraine and TTH) among undergraduate medical students. This study also aims to act as a nidus for future large-scale studies among medical students for necessary intervention. This study is in line with STROBE guidelines. 6  where n is calculated sample size; Z is 1.96 at 95% confidence interval (CI); p is expected prevalence of students having headache, 50%; Considering 8% nonresponse rate, the final sample size was 361.

| METHODS
We used convenient sampling to select students. List of students (from the first year to final year) from each college was accessed and respondents were selected. Through this process, 361 individuals were selected.

| Study tool
Headache Screening Questionnaire-English Version (HSQ-EV), based on ICHD-3 beta, is a 10-item questionnaire that is a sensitive screening tool. This 10-item questionnaire is used to screen for both migraine and TTHs. A particular score has been assigned to each answer of a question and according to the answers given by the responders total score is calculated. The cut-off point for definite diagnosis is eight and for probable diagnosis is six. When all the criteria based on ICHD-3 beta were met, the score received would be eight for both migraine and TTH and when the score received is at least six points, migraine and TTH are considered to be probable migraine and probable TTH. 8 Along with the HSQ-EV, questions of sociodemographic were also included in the questionnaire. The study tool is available as Supporting Information: File S1.

| Dependent and independent variables
All of the dependent variables (DVs) and independent variables (IVs) were dichotomous and categorical except for age. DVs were diagnosis of migraine and diagnosis of TTH. IVs included age, sex, year of study, involvement in extracurricular activities, daily exercise/ yoga/outdoor sports, having a demanding family responsibility, food preference, and smoking habit. These IVs were selected after literature review.

| Analytical strategy
Frequency was calculated for all the IVs and lifetime prevalence was calculated for DVs with CI. Binomial logistic regression was used to see how DVs and IVs affected each other, univariate analysis gave crude odds ratio and multivariate analysis gave adjusted odds ratio (AOR; no migraine/TTH was coded as 0 and presence of migraine/ TTH was coded as 1. Data were refined in excel then imported to SPSS 20 for the analysis. Diagnosis of definite and probable migraine was combined in the estimation of prevalence and other analyses.
The same was done for TTH.

| RESULTS
Out of 361 students, a total of 352 individuals who responded were part of this study. Out of the included individuals 229 (65.1%) were males and 123 (34.9%) were females. Age of the participants ranged from 17 to 28 with a mean age of 21.72 ± 1.601 years (mean ± SD). The rest of the sociodemographic details are listed in Table 1.

| Prevalence of migraine and TTH
The prevalence of migraine was found to be 15.3% (CI: 11.7-19.3). A total of 25 out of 123 females and 29 out of 229 males had migraine.
Similarly, 27 out of 144 preclinical students and 27 out of 208 clinical students were seen to have migraine headache.
A total of 52 out of 123 females and 90 out of 229 males were screened to have TTH. A total of 58 out of 144 preclinical students and 84 out of 208 clinical students were found to have TTH ( Table 2).

| Regression analysis result of migraine
Findings of univariate analysis showing crude odds ratio are presented in Table 3.  Table 4.

| DISCUSSION
In this article, we have studied the prevalence of migraine and TTH by using the HSQ-EV questionnaire based upon the ICHD-3 beta.
Migraine, probable migraine, no migraine, TTH, probable TTH, and no TTH were the possible domains in which the respondents could be grouped through this questionnaire. Probable migraine refers to migraine-like attacks but without one of the features required to meet all the criteria for migraine, and also not fulfilling the criteria for any other headache types. 4 This study done among the medical students in Kathmandu is the first of its kind in the country. In our study, the prevalence of Migraine was found to be 15.3% and the prevalence of TTH was found to be 40.3%. Furthermore, among similar studies done across the world, the prevalence of migraine in Enugu, Nigeria was similar. 9 While some studies from India, 10 Saudi Arabia, 11 Turkey, 12 and Kuwait 13 shows a higher prevalence of migraine among medical students, whereas another study from South-East Iran 14 shows lower prevalence. This wide range of prevalence across the world may be attributed to the geography and altitude, 15 cultural differences, data collected at different periods of time, and different tools of measurement.
Another significant finding of this study suggested that females are at 2.11 more odds (AOR) of experiencing migraine headaches compared to males. Similar findings were observed in other studies. 11,13,16 Migraine often has a close relationship with the menstrual cycle of women, 4 however, to include the menstrual history to differentiate the classical migraine from menstrual migraine was out of the scope of this current study. The mechanism behind headache during menstruation is not entirely clear but could be traced back to estrogen deficiency 17 and this is yet to be explored in future studies. Our study reports that nonhostellers are at 2.77 more odds (AOR) of having migraine which is in disagreement with a study by Narang and Jahan, 18 which reported that nonhostellers have less level of stress as well as sleep disturbance than fellow hostelers and that stress and sleep disturbances are important trigger factors for migraine. 11,16,19 Comparing the results with that of study done on general population in Nepal also shows female preponderance, while the study has reported a higher prevalence (1-year prevalence) than the findings of this study. This might be attributed to the altitude factors and easy accessibility of health facilities among medical students compared to general population. 15 National level also study shows that odds of having migraine increases with increasing household altitudes but this could not be explored through this study as samples are taken from single city. 15,20 No significant difference was observed in year of study (preclinical or clinical) and migraine which is contrary to the previous studies; one Croatian study by Galinovic 21 showed that more first-year students visited clinics for migraine than final-year students and another study by Ibrahim et al. 11 reported higher migraine in second- year students. This observation was likely due to increased stress among new medical students due to changes in the environment and strong academic demand for those coming from less stressful highschool days. However, in our study, the COVID-19 pandemic may have affected the finding, as the schedules were less hectic and the new coming medical students had ample time to adjust to the medical setting. The prevalence of TTH was found to be 40.3% in the current study within the global prevalence rate of 12%-78%. 22 Studies from Syria, 23 Turkey, 24  The major weakness of this study is that it has used a convenient sampling method and results might not be generalizable. Nonrandomized sampling method was used in this study (done among medical students) as this study is first of its kind in Nepal and the trend of probable outcome was not known. So, to obtain basic data quickly and with less complications convenient sampling was used. However, the basic data obtained from this study can act as nidus for future studies which will be more statistically rigorous and more generalizable.

| CONCLUSION
In a nutshell, our study found the prevalence of migraine and TTH to be 15.3% and 40.3% respectively. There were higher odds of experiencing migraine headache with increasing age, higher odds in students who do not stay at hostel and females were at more odds than males. However, no such significant difference was observed in the case of TTH.

SUPPORTING INFORMATION
Additional supporting information can be found online in the Supporting Information section at the end of this article.